Transparent endoscope head defining a focal length

Abstract

A catheter configured for imaging objects substantially in focus is described herein. An imaging device is disposed on the distal end of the catheter. The imaging device has an effective focal plane that is located in front of the imaging device. The catheter also includes a transparent focal instrument that has an outer periphery that is positioned at the effective focal plane of the imaging device, to enable objects in contact with the outer periphery of the transparent focal instrument to be imaged substantially in focus.

What is claimed is: 
     
       1. A catheter configured for imaging objects substantially in focus, comprising:
 a) an imaging device disposed on a distal end of the catheter, the imaging device having an effective focal plane; 
 b) a transparent focal instrument coupled to the catheter, the transparent focal instrument having an outer periphery, wherein a length from the imaging device to the outer periphery of the transparent focal instrument is equal to the distance from the imaging device to the effective focal plane of the imaging device; wherein when the outer periphery is positioned at the effective focal plane of the imaging device, it enables objects in contact with the outer periphery of the transparent focal instrument to be imaged substantially in focus; and 
 c) an open channel having a first orifice disposed about a side surface of the catheter in fluid communication with a second orifice on a distal end of the catheter, wherein the imaging device is located inside an inflatable balloon and wherein the inflatable balloon is configured to cover the first orifice of the catheter when deflated for limiting fluid communication in the open channel. 
 
     
     
       2. The catheter of  claim 1 , wherein the imaging device comprises a solid state imaging device including an imaging array and a graduated refractive index lens optically coupled to the imaging array of the solid state imaging device. 
     
     
       3. The catheter of  claim 2 , wherein the transparent focal instrument is coupled to the graduated refractive index lens. 
     
     
       4. The catheter of  claim 1 , wherein the imaging device includes at least two imaging devices. 
     
     
       5. The catheter of  claim 1 , wherein the imaging device is configured to image in a lateral direction with respect to a longitudinal axis of the catheter. 
     
     
       6. A catheter configured for imaging objects substantially in focus, comprising: a) an imaging device disposed on a distal end of the catheter, the imaging device having an effective focal plane; b) a transparent focal instrument coupled to the catheter, the transparent focal instrument having first and second positions, wherein when disposed in the second position, the transparent focal instrument has a length that is equal to the distance between the imaging device and the effective focal plane of the imaging device and is positioned at the effective focal plane of the imaging device to enable a target object in contact with an outer periphery of the transparent focal instrument to be imaged substantially in focus, wherein the transparent focal instrument comprises an inflatable balloon; and c) a channel having a first orifice disposed about a side surface of the catheter adjacent a distal end of the catheter, and a second orifice disposed about a distal end of the catheter, the first orifice being in fluid communication with the second orifice, wherein when the inflatable balloon is disposed in the second position, the channel extends from a first side of the inflatable balloon to a second side of the inflatable balloon to permit fluids within a vessel of a patient to pass from one side of the inflatable balloon to the second side of the inflatable balloon, wherein when the inflatable balloon is disposed in the first position, the inflatable balloon is configured to cover the first orifice of the catheter for limiting fluid communication in the channel. 
     
     
       7. A method for imaging with a catheter, comprising:
 a) providing a catheter having a channel disposed therein and a transparent focal instrument, the transparent focal instrument comprising first and second positions wherein when the transparent focal instrument is disposed in the first position, the transparent focal instrument covers an opening of the channel and wherein when the transparent focal instrument is disposed in the second position, the transparent focal instrument does not cover the opening of the channel and has an outer periphery with a length equal to the length of the effective focal plane, the transparent focal instrument being positioned at an effective focal plane of an imaging device; 
 b) inserting the catheter into a cavity of a patient while the transparent focal instrument is disposed in the first position; 
 c) after inserting the catheter into the cavity of the patient, disposing the transparent focal instrument in the second position thereby occluding the cavity of the patient with the transparent focal instrument and removing the transparent focal instrument from the opening of the channel; and 
 d) imaging a target object. 
 
     
     
       8. The method of  claim 7 , wherein the transparent focal instrument comprises a balloon. 
     
     
       9. The method of  claim 8 , wherein positioning the outer periphery of the transparent focal instrument includes inflating the balloon disposed on the catheter to move a distal end of the balloon in contact with the target object. 
     
     
       10. The method of  claim 7 , wherein the transparent focal instrument comprises a transparent balloon having an inflated length substantially equivalent to the effective focal plane of the imaging device. 
     
     
       11. The method of  claim 7 , wherein the imaging device is configured to image objects lateral to a longitudinal axis of the catheter. 
     
     
       12. The method of  claim 7 , wherein positioning the outer periphery of the transparent focal instrument includes inflating a balloon disposed on the catheter to move a distal end of the balloon in contact with the target object. 
     
     
       13. The method of  claim 12 , wherein the transparent focal instrument is substantially solid. 
     
     
       14. The method of  claim 12 , further comprising a plurality of imaging devices disposed about an exterior of the catheter and a plurality of balloons, each balloon enclosing a single imaging device.